Polarity effects in ZnO nanowires

Polarity effects in ZnO nanowires
Polarity control in wide band gap semiconductors like GaN and ZnO is essential for their integration into a large number of electronic and optoelectronic devices [1]. Following the demonstration in Vincent Consonni's team that ZnO nanowires grown by chemical bath deposition can be of either oxygen or zinc polarity [2], we have conducted several investigations aiming at elucidating the effects of the polarity on their growth mechanisms and on their properties.

We have shown the polarity transfer from a polycrystalline ZnO seed layer into ZnO nanowires by anomalous x-ray diffraction in synchrotron, favouring a statistical analysis over 10 million of nano-objects [3].

We have also revealed that Zn-polar ZnO nanowires elongate with a larger growth rate than O-polar ZnO nanowires. A theoretical modelling of the growth process has allowed us to attribute that difference to a larger surface reaction rate constant in the case of Zn-polar ZnO nanowires than in the case of O-polar ZnO nanowires [4].

These ongoing investigations with strong fundamental and applicative interests are specifically conducted in the framework of the project ANR ROLLER (2018 – 2021) that is in collaboration with Institut Néel, Institut des Nanotechnologies de Lyon, and LGEF.

[1] J. Zuniga-Perez, V. Consonni, L. Lymperakis, X. Kong, A. Trampert, S. Fernandez-Garrido, O. Brandt, H. Renevier, S. Keller, K. Hestroffer, M.R. Wagner, J.S. Reparaz, G. Akyol, S. Rajan, S. Rennesson, T. Palacios, and G. Feuillet, « Polarity in GaN and ZnO: Theory, measurement, growth, devices », Applied Physics Reviews 3, 041303 (2016).
[2] V. Consonni, E. Sarigiannidou, E. Appert, A. Bocheux, S. Guillemin, I.C. Robin, J. Kioseoglou, and F. Robaut, « Selective Area Growth of Well-Ordered ZnO Nanowire Arrays with Controllable Polarity », ACS Nano 8, 4761-4770 (2014).
[3] S. Guillemin, R. Parize, J. Carabetta, V. Cantelli, D. Albertini, B. Gautier, G. Brémond, D.D. Fong, H. Renevier, and V. Consonni, « Quantitative and Simultaneous Analysis of the Polarity of Polycrystalline ZnO Seed Layers and Related Nanowires Grown by Wet Chemical Deposition », Nanotechnology 28, 095704 (2017).
[4] T. Cossuet, E. Appert, J.L. Thomassin, and V. Consonni, « Polarity-Dependent Growth Rates of Selective Area Grown ZnO Nanorods by Chemical Bath Deposition », Langmuir 33, 6269-6279 (2017).